Freakonomics in the N.Y. Times: The Shangri-La Diet

Our latest New York Times Magazine column, to be published on Sun., Sept. 11, explores the work of Seth Roberts, a Berkeley psychologist who has used self-experimentation to arrive at, among other things, a diet that may prove revolutionary. Or at least very entertaining. Here is some additional information about Roberts and his work. I first learned of Roberts from the always-excellent Marginal Revolution; thank you, gentlemen. Levitt and I subsequently spent some time with Roberts in California, while on our recent book tour — so there’s yet another reason the tour was well worthwhile. We’ve also invited Roberts to guest-blog here, so keep an eye out for him in the coming days.


After playing some poker for the greater good of Pokeronomics and getting fat sitting in my chair, lo and behold, I find a freaky new diet. Freakonomics for life!

Andrew Gelman

It's great to see Seth's work getting more publicity. You might be interested in the discussions on our blog here and here about Seth's studies and, more generally, desirable sample sizes for scientific studies. Self-experimentation, with n=1, is the opposite of the usual "NIH" paradigm of medical research. See also here for some other comments on the topic.

P.S. The publicizing of Seth's work also is an interesting example of information transmission. Seth published a paper in Behavioral and Brain Sciences--a top journal, but not enough to get the work much publicity. I posted a link to it on our blog (circulation 200/day), it was picked up by Alex at Marginal Revolution (circulation 10,000/day) and from there was noticed by a columnist for the New York Times (circulation ~ 2 million/day). But I think the high quality of Seth's article in BBS, with all its experimental data and scientific context, was crucial, in convincing the two levels of gatekeeper--Alex and Stephen--that the work could be taken seriously.



Seth's article in Behavioral and Brain Sciences is a fascinating read: one learns of Seth's anecdotal successes and failures; while science gains from the mountains of data he collected for over 10 years(!).

It's rare to have an individual curious and patient enough to attempt self-experimentation like this paired with sound heuristic techniques. Even rarer is the individual capable of distilling and connecting the newly found evidence to esoteric theories in psychology and biology.

'Hats Off' to Seth! And Kudos to Levitt & Dubner for their excellent NYT article and for their remarkably wonderful book.

Paul Bowers

interesting article. i've read dr. roberts' papers on his self-experimentation, but i still have some questions about his flavor-calorie learning theory.

if our bodies learn to associate flavor with the amount of calories in our food, and new or "flavorless" foods don't send the fat storage signal, then this must mean that flavor controls insulin response (since insulin is the hormone that controls fat storage). if flavor controls insulin response, than we should see an insulin response to the flavor without any caloric intake, right? i'd really like to get a metabolic explanation (rather than an evolutionary one) to this phenomena.

Paul Bowers

maybe i'm misunderstanding this theory. calorie-associated flavors raise the set point, unless there is no flavor to associate with (i.e. fructose water). but what is the metabolic mechanism that regulates the set point? and how is hunger being regluated?


That was a fascinating article. I also checked out his paper "What Makes Food Fattening? A Pavlovian Theory of Weight Control" in the freakonomics website which goes into his Shangri-La diet in greater detail. One thing I'm not totally clear about is whether it is the sweetness of unflavored fructose water itself or the calories in it without the flavor that suppresses appetite and lowers the set point. Will an artificial sweetener with almost no calorie like sucralose (Splenda) mixed in plain water will work just as well as unflavored water? I may just have to experiment on myself to find out!


The fact that the readjustment of the set point is a learned response suggests to me that one should not see an insulin rise initially to a new flavor without calories and that only after the calories have been associated with the flavor over time will the insulin rise with the flavor alone. One should then be able to test this hypothesis by measuring insulin levels in volunteers first exposed to a flavor without calories, combine the flavor with calories to form the association then retest the insulin levels when the volunteers are exposed to the flavor alone. all this sounds more like a neurophysiological response than a pure metabolic one. Perhaps cutting the vagus nerves to the pancreas will prevent the resetting of the set point in response to flavors being associated with calories according to Robert's theory. Physiologists, write those grants so you can do these experiments!


perniciousness of "n of 1" problem--


Another very interesting book on self experimentation is "Who Goes First?" by Lawrence Altman.

He focuses on self experimentation where there was some element of danger to the volunteers. From what I remember of the book, his goal is to show that self-experimentation is a centuries old tradition in science and is still alive although modern internal review boards and ethicists are trying to stop it. (for both good and bad reasons)

I was amazed both at some of the disturbing self experiments and what scientists proved through this method that couldn't have been done or ethically done any other way.


While I applaud the two of you, Stephen and Steven, and your work and your book, I find your piece today quite TROUBLING!

Ingesting fructose on a regular basis could be quite dangerous, whether it's taken in liquid or solid form.

I just spent three-four years researching and writing my book SUGAR SHOCK! and I've learned some scary things about fructose. (I won't get near it.)

Please see my blog entry,
in which I quote 3 experts, who comment on Seth Roberts's dismal diet.

NO ONE should follow it!

Please, I urge you both, learn more about this subject before inviting Roberts on your blog to spread the word about his so-called "diet."

I'd be happy to hook you up with several experts to discuss fructose and its dangers.


Jimmy Moore

I cannot disagree more regarding a "diet" that urges people to drink sugar water to help them lose weight.

As a 180-pound low-carb weight loss success story in 2004, I credit overcoming my addiction to sugar as a major reason why I was so successful in my weight loss and my healthy has improved dramatically. Sugar is a lot more destructive to our bodies than people are willing to admit and any weight loss program that advocates consuming sugar as a major tenet causes me to become concerned.

Please delve a little deeper into the science of this "diet" plan and see the long-term affects it will have on people who do it. I am disturbed by the potential harm that can and will be done to the people attempting to lose weight following the Roberts sugar diet. Hopefully you will find the error of your ways and write a follow-up article condemning it as it should be.

THANKS for allowing me to share my thoughts!

Jimmy Moore, "Livin' La Vida Low-Carb Man"



My favorite self-experimenter is Barry Marshall, the man who proved that most ulcers are caused by bacteria. To prove his theory, he ingested the bacteria, got an ulcer, drank antibiotics, and cured his ulcer. For more information:


You don't have to use fructose. You can also ingest a tablespoon of olive oil in between meals instead, according to Roberts.


Roberts' theory seems to make good sense, and more importantly, it does NOT involve any unorthodox dietary schemes or deprivation, which rarely, if ever, work over the long term.

My husband and I already consume a very healthy diet, but as we've approached 50 yrs. of age and our metabolisms have slowed, we are slowly gaining unwelcome pounds.

The "Pavlovian Theory" paper does not state how much granulated fructose to dissolve in how much water to consume daily to test Roberts' theory for ourselves. We haven't a clue how much fructose = 0.6mJ, and we don't know if 140 kcal is a teaspoon in 4 oz. of water or ... ?

Can anyone translate this into kitchen measurements?


I dare say that a lot of nutritionists would disagree with low-carb Atkins-like diets, whose science they find on far shakier ground than Robert's diet. He backs his findings up very thoroughly with a review of past scientific research in his paper What makes Food Fattening: A Pavlovian Theory of Weight Control" found at


Connie said... "Ingesting fructose on a regular basis could be quite dangerous, whether it's taken in liquid or solid form."

So do the olive oil or use table sugar instead. The trick appears to be giving your body calories without an associated flavour hit. Your body believes that you're in 'lean times' and lowers you set point to regulate your hunger and have you survive on less food.

And what are you suggesting as an alternative? Stomach staples? Perhaps we have to buy your book to find out?

Jimmy Moore said... "I cannot disagree more regarding a "diet" that urges people to drink sugar water to help them lose weight. As a 180-pound low-carb weight loss success story in 2004, I credit overcoming my addiction to sugar as a major reason why I was so successful in my weight loss and my healthy has improved dramatically."

You can disagree as much as you want - but if the diet works, it works. I don't think ingesting olive oil, fructose or table sugar is anywhere near as bad as some of the stuff we put in our mouths every day.

If this diet does indeed cause people to eat less, the positive effects of weight loss and well being would outweigh any nebulous and ill formed concerns about "dangerous fructose" or "sugar addiction".

To everyone here I say: try it. It's not going to kill you. If it doesn't work, stop it. This should be easy to do, because (unlike the Aitkens diet) the core of the diet does not involve a pleasurable indulgence. Drinking sugar water or eating olive oil is quite bland.

For what it's worth, I have found the best weight control mechanism is exercise and moderating how much I eat. I don't watch what I eat - I eat when I feel hungry and I eat whatever I like, but I eat appropriate quantities. Coupled with a good amount of exercise that I enjoy (cycling, running, lifting weights), I have no problem with weight.

Weight loss is always a matter of burning more than you put in. Whether you get there by tricking your body into feeling less hungry or exercising madly, as long as you're eating nutritionally decent food at the same time, you'll be okay.

Luke (



When food packages write "calories," they actually mean kilocalories or kcal for short. Roberts states that he had to take 140 kcal or 140 'calories" a day in divided doses of unflavored fructose to suppress his appetite and lose weight. One small packet of Estee Fructose contains 3 grams or 10 "calories" or 10 kcal. If you take it in between meals (at least 3 times), then that translates to about 46.7 kcal or "calories" per serving. A 12 fluid ounce can of Classic Coke contains 162 calories to give you a very rough idea of the total amount of sugar you are ingesting per day. Therefore, I would dissolve 4.5 packets of fructose or approximately 15.5 grams in a glass of water and drink that at least 1 hour before breakfast, lunch and dinner to kill your appetite.


In his paper, he has three recommendations as far as his Shangri-La diet:

1. Eat new foods. His theory implies that no food with a new flavor is fattening.

2. Vary the flavor of foods eaten repeatedly to minimize flavor-calorie associations.

3. Consume calories with no flavor associations. Ingesting a small fraction of one's daily caloric intake in the form of unflavored fructose water or flavorless vegetable oils such as olive oil will accomplish this.

I see nothing in his recommendations that is inherently unhealthy. His recommendations in fact would enable people to stick to their favorite diet if they supplement it with his advice, whether they be low-carb or low-fat or low calorie diets because it would decrease the temptation to break their diet from hunger. Demonizing sugars and carbs as Jimmy Moore and Connie do above witholut understanding the science behind Robert's theory only makes their recommendations far less believable to others.



Sorry, that should be approximately 13.5 to 14 grams of fructose dissolved in plain water instead of 15 to 16 grams per serving if you are going to take it three times a day between meals to give you a total of approximately 140 kcal a day.


Recently researchers in Texas reported that drinking diet soda caused weight gain. There had previously been other research on artificial sweeteners to this effect.

One hypothesis the researchers put forth was that when “sweetness” no longer seems to be associated with calories to be burned by the body, the body abandons that clue as meaningful, and doesn't try to restrict the intake of sweets as strongly as before.

I don't know if this is true, but it sounds like the inverse of Roberts' tactic of disassociating calories from taste.

Roberts' diet sounds pretty wacky to me, but it has one unique aspect: it might lend itself to double-blind testing more easily than most diets by using mineral oil or artificial sweeteners in place of vegetable oil and sugar.